Product Preview
WM8777
DE-EMPHASIS MODE
A digital De-emphasis filter may be applied to each DAC channel. The De-emphasis filter for each
stereo channel is enabled under the control of DEEMP[3:0]. DEEMP[0] enables the de-emphasis
filter for channel 1, DEEMP[1] enables the de-emphasis filter for channel 2, DEEMP[2] enables the
de-emphasis filter for channel 3 and DEEMP[3] enables the de-emphasis filter for channel 4.
REGISTER ADDRESS
(17h)
BIT
LABEL
DEFAULT
DESCRIPTION
3:0
DEEMP[3:0]
0000
De-emphasis mode select:
DAC Control
DEEMPH[0] = 1, enable De-
emphasis on DAC1.
DEEMPH[1] = 1, enable De-
emphasis on DAC2.
DEEMPH[2] = 1, enable De-
emphasis on DAC3.
DEEMPH[3] = 1, enable De-
emphasis on DAC4.
Table 55 De-emphasis Register
Refer to Figure 37, Figure 38, Figure 39, Figure 40, Figure 41 and Figure 42 for details of the De-
Emphasis modes at different sample rates.
DAC OUTPUT CONTROL
The DAC output control word determines how the left and right inputs to the audio Interface are
applied to the left and right DACs:
REGISTER ADDRESS
(15h)
BIT
LABEL
DEFAULT
DESCRIPTION
8:5
PL[3:0]
1001
Left
Output
Right
Output
PL[3:0]
DAC Attenuation Control
0000
0001
0010
0011
0100
0101
0110
0111
1000
1001
1010
1011
Mute
Left
Mute
Mute
Mute
Mute
Left
Right
(L+R)/2
Mute
Left
Left
Right
(L+R)/2
Mute
Left
Left
Right
Right
Right
Right
Left
Right
(L+R)/2
1100
1101
Mute
Left
(L+R)/2
(L+R)/2
1110
1111
Right
(L+R)/2
(L+R)/2
(L+R)/2
Table 56 DAC Attenuation Register (PL)
DAC OVERSAMPLING RATE SELECT
Control bit DACOSR allow the user to select the DAC internal signal processing oversampling rate.
Operation is described in Table 18 and Table 19.
REGISTER ADDRESS
BIT
LABEL
DEFAULT
DESCRIPTION
DAC oversampling rate select
0: 128x oversampling
(19h)
3
DACOSR
0
DAC Oversampling
Rate Select
1: 64x oversampling
Table 57 DAC Oversampling Rate
PP Rev 1.94 November 2004
59
w
WOLFSON [ WOLFSON MICROELECTRONICS PLC ]
